Splenectomy in patients with massive splenic injuries is associated with the risk of postoperative hy- posplenism syndrome. The aim of the work was to improve methods for the prevention of postoperative hyposplenism in traumatic splenic injuries. At the first stage, it was found that the average length of the second-order splenic arteries is 1.3 ± 0.2 cm, from which small vessels with a diameter of 120.8 ± 29.1 μm depart, which participate in the formation of arteriovenous complexes located under the capsule of the organ. At the second stage, methods for preventing postoperative hyposplenism in case of traumatic injuries of the organ of degrees III–V in patients of the main group were improved and implemented. It was established that the presence of spleen tissue with main blood flow ensures the stability of the organ' s filtering function. At the same time, splenectomy was accompanied by serious disorders in the form of the appearance of destroyed and pathologically altered erythrocytes in the peripheral blood. Also, according to the results of sonographic examination, an increase in the area of the remaining spleen parenchyma was detected in the case of subtotal resection of the organ with the formation of parenchymal couplings around the second-order arteries by 21.4% after two months, and by 40.2% after a year. In the case of subtotal spleen resection with covering the cut plane with an adhesive hemostatic plate, the area increase after 2 months was 27.3%, after a year - 49.1%. The implementation of the developed methods for the prevention of postoperative hyposplenism in patients with traumatic spleen injury of III–V degree allows to reduce the frequency of complications in the early postoperative period in the case of isolated injury from 29.4% to 5.0% and in the long-term postoperative period from 30.0% to 2.9%.